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Apatosaurus excelsus

OLogy Series
extinct animal
card
006

Apatosaurus excelsus

OLogy Series
extinct animal

This famous long-necked, long-tailed wonder belongs to a group called "sauropods." This group of animals are the largest to ever roam our planet. Apatosaurus was an herbivore (plant-eater) and it walked on all four legs. To reach tree tops, it may have reared up on its hind legs and used its tail as a "third leg."

Putting Their Heads Together
When the first Apatosaurus skeleton was discovered, it was headless. Scientists believed it was related to Camarasaurus, which had been dug up with its head attached. So in Museum displays, a Camarasaurus-like head (bottom) was attached to an Apatosaurus body. Later, paleontologists found a "mystery skull" near an Apatosaurus body. This skull looked more like it belonged to another dinosaur, Diplodocus (top) than to a Camarasaurus. By this time, scientists had figured out that Apatosaurus was more closely related to Diplodocus than Camarasaurus. The Camarasaurus-like heads were removed from the Apatosaurus skeletons in Museums and replaced with casts of the "mystery skull."

Bye-Bye, Brontosaurus!
Scientists used to think that Brontosaurus and Apatosaurus were two different types of dinosaur. Once they figured out that the fossils belonged to the same kind of dinosaur, they went with the first name Apatosaurus (from 1877) instead of Brontosaurus (from 1878). The name Brontosaurus is now "extinct," except, of course, in reruns of The Flintstones cartoons.

How much do paleontologists think an Apatosaurus weighed?

27 to 36 kilograms (60 to 80 pounds)

2,700 to 3,600 kilograms (6,000 to 8,000 pounds)

27,000 to 36,000 kilograms (60,000 to 80,000 pounds)

Are you right?

Correct!

Scientists think that an adult Apatosaurus would have weighed between 27,000 and 36,000 kilograms (60,000 and 80,000 pounds). That's a lot of dinosaur!

Apatosaurus was mostly a swamp dweller. The water in the swamp helped support this enormous dinosaur's body.

Fact
or
Fiction
?

Fiction

Most sauropod trackways (sets of footprints) show that these animals hung out on land, as well as in water.

Scientific Name: Apatosaurus excelsus 
Pronunciation: uh-PAT-oh-SAW-rus ek-SELL-sus
Meaning: "deceptive lizard"
Locality Found: Colorado, Wyoming, Utah
Age: Late Jurassic, 154 to 144 million years ago
Length: 22 meters (73 feet) long
Height: 4.5 meters (15 feet) tall
Characteristics: herbivorous dinosaur that probably spent most of its time reaching for leaves with its long neck

Image credits: Rick Spears.